/**
 * This file is from Mozilla pdf.js project
 * https://github.com/mozilla/pdf.js
 * Licensed under Mozilla License
 * https://github.com/mozilla/pdf.js/blob/master/LICENSE
 */
/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
/* Copyright 2012 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/* globals VBArray, PDFJS */

'use strict';

// Initializing PDFJS global object here, it case if we need to change/disable
// some PDF.js features, e.g. range requests
if (typeof PDFJS === 'undefined') {
   (typeof window !== 'undefined' ? window : this).PDFJS = {};
}

// Checking if the typed arrays are supported
(function checkTypedArrayCompatibility() {
   if (typeof Uint8Array !== 'undefined') {
      // some mobile versions do not support subarray (e.g. safari 5 / iOS)
      if (typeof Uint8Array.prototype.subarray === 'undefined') {
         Uint8Array.prototype.subarray = function subarray(start, end) {
            return new Uint8Array(this.slice(start, end));
         };
         Float32Array.prototype.subarray = function subarray(start, end) {
            return new Float32Array(this.slice(start, end));
         };
      }

      // some mobile version might not support Float64Array
      if (typeof Float64Array === 'undefined')
         window.Float64Array = Float32Array;

      return;
   }

   function subarray(start, end) {
      return new TypedArray(this.slice(start, end));
   }

   function setArrayOffset(array, offset) {
      if (arguments.length < 2)
         offset = 0;
      for (var i = 0, n = array.length; i < n; ++i, ++offset)
         this[offset] = array[i] & 0xFF;
   }

   function TypedArray(arg1) {
      var result;
      if (typeof arg1 === 'number') {
         result = [];
         for (var i = 0; i < arg1; ++i)
            result[i] = 0;
      } else if ('slice' in arg1) {
         result = arg1.slice(0);
      } else {
         result = [];
         for (var i = 0, n = arg1.length; i < n; ++i) {
            result[i] = arg1[i];
         }
      }

      result.subarray = subarray;
      result.buffer = result;
      result.byteLength = result.length;
      result.set = setArrayOffset;

      if (typeof arg1 === 'object' && arg1.buffer)
         result.buffer = arg1.buffer;

      return result;
   }

   window.Uint8Array = TypedArray;

   // we don't need support for set, byteLength for 32-bit array
   // so we can use the TypedArray as well
   window.Uint32Array = TypedArray;
   window.Int32Array = TypedArray;
   window.Uint16Array = TypedArray;
   window.Float32Array = TypedArray;
   window.Float64Array = TypedArray;
})();

// URL = URL || webkitURL
(function normalizeURLObject() {
   if (!window.URL) {
      window.URL = window.webkitURL;
   }
})();

// Object.create() ?
(function checkObjectCreateCompatibility() {
   if (typeof Object.create !== 'undefined')
      return;

   Object.create = function objectCreate(proto) {
      function Constructor() {}
      Constructor.prototype = proto;
      return new Constructor();
   };
})();

// Object.defineProperty() ?
(function checkObjectDefinePropertyCompatibility() {
   if (typeof Object.defineProperty !== 'undefined') {
      var definePropertyPossible = true;
      try {
         // some browsers (e.g. safari) cannot use defineProperty() on DOM objects
         // and thus the native version is not sufficient
         Object.defineProperty(new Image(), 'id', { value: 'test' });
         // ... another test for android gb browser for non-DOM objects
         var Test = function Test() {};
         Test.prototype = { get id() { } };
         Object.defineProperty(new Test(), 'id',
            { value: '', configurable: true, enumerable: true, writable: false });
      } catch (e) {
         definePropertyPossible = false;
      }
      if (definePropertyPossible) return;
   }

   Object.defineProperty = function objectDefineProperty(obj, name, def) {
      delete obj[name];
      if ('get' in def)
         obj.__defineGetter__(name, def['get']);
      if ('set' in def)
         obj.__defineSetter__(name, def['set']);
      if ('value' in def) {
         obj.__defineSetter__(name, function objectDefinePropertySetter(value) {
            this.__defineGetter__(name, function objectDefinePropertyGetter() {
               return value;
            });
            return value;
         });
         obj[name] = def.value;
      }
   };
})();

// Object.keys() ?
(function checkObjectKeysCompatibility() {
   if (typeof Object.keys !== 'undefined')
      return;

   Object.keys = function objectKeys(obj) {
      var result = [];
      for (var i in obj) {
         if (obj.hasOwnProperty(i))
            result.push(i);
      }
      return result;
   };
})();

// No readAsArrayBuffer ?
(function checkFileReaderReadAsArrayBuffer() {
   if (typeof FileReader === 'undefined')
      return; // FileReader is not implemented
   var frPrototype = FileReader.prototype;
   // Older versions of Firefox might not have readAsArrayBuffer
   if ('readAsArrayBuffer' in frPrototype)
      return; // readAsArrayBuffer is implemented
   Object.defineProperty(frPrototype, 'readAsArrayBuffer', {
      value: function fileReaderReadAsArrayBuffer(blob) {
         var fileReader = new FileReader();
         var originalReader = this;
         fileReader.onload = function fileReaderOnload(evt) {
            var data = evt.target.result;
            var buffer = new ArrayBuffer(data.length);
            var uint8Array = new Uint8Array(buffer);

            for (var i = 0, ii = data.length; i < ii; i++)
               uint8Array[i] = data.charCodeAt(i);

            Object.defineProperty(originalReader, 'result', {
               value: buffer,
               enumerable: true,
               writable: false,
               configurable: true
            });

            var event = document.createEvent('HTMLEvents');
            event.initEvent('load', false, false);
            originalReader.dispatchEvent(event);
         };
         fileReader.readAsBinaryString(blob);
      }
   });
})();

// No XMLHttpRequest.response ?
(function checkXMLHttpRequestResponseCompatibility() {
   var xhrPrototype = XMLHttpRequest.prototype;
   if (!('overrideMimeType' in xhrPrototype)) {
      // IE10 might have response, but not overrideMimeType
      Object.defineProperty(xhrPrototype, 'overrideMimeType', {
         value: function xmlHttpRequestOverrideMimeType(mimeType) {}
      });
   }
   if ('response' in xhrPrototype ||
      'mozResponseArrayBuffer' in xhrPrototype ||
      'mozResponse' in xhrPrototype ||
      'responseArrayBuffer' in xhrPrototype)
      return;
   // IE9 ?
   if (typeof VBArray !== 'undefined') {
      Object.defineProperty(xhrPrototype, 'response', {
         get: function xmlHttpRequestResponseGet() {
            return new Uint8Array(new VBArray(this.responseBody).toArray());
         }
      });
      return;
   }

   // other browsers
   function responseTypeSetter() {
      // will be only called to set "arraybuffer"
      this.overrideMimeType('text/plain; charset=x-user-defined');
   }
   if (typeof xhrPrototype.overrideMimeType === 'function') {
      Object.defineProperty(xhrPrototype, 'responseType',
         { set: responseTypeSetter });
   }
   function responseGetter() {
      var text = this.responseText;
      var i, n = text.length;
      var result = new Uint8Array(n);
      for (i = 0; i < n; ++i)
         result[i] = text.charCodeAt(i) & 0xFF;
      return result;
   }
   Object.defineProperty(xhrPrototype, 'response', { get: responseGetter });
})();

// window.btoa (base64 encode function) ?
(function checkWindowBtoaCompatibility() {
   if ('btoa' in window)
      return;

   var digits =
      'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';

   window.btoa = function windowBtoa(chars) {
      var buffer = '';
      var i, n;
      for (i = 0, n = chars.length; i < n; i += 3) {
         var b1 = chars.charCodeAt(i) & 0xFF;
         var b2 = chars.charCodeAt(i + 1) & 0xFF;
         var b3 = chars.charCodeAt(i + 2) & 0xFF;
         var d1 = b1 >> 2, d2 = ((b1 & 3) << 4) | (b2 >> 4);
         var d3 = i + 1 < n ? ((b2 & 0xF) << 2) | (b3 >> 6) : 64;
         var d4 = i + 2 < n ? (b3 & 0x3F) : 64;
         buffer += (digits.charAt(d1) + digits.charAt(d2) +
            digits.charAt(d3) + digits.charAt(d4));
      }
      return buffer;
   };
})();

// window.atob (base64 encode function) ?
(function checkWindowAtobCompatibility() {
   if ('atob' in window)
      return;

   // https://github.com/davidchambers/Base64.js
   var digits =
      'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
   window.atob = function (input) {
      input = input.replace(/=+$/, '');
      if (input.length % 4 == 1) throw new Error('bad atob input');
      for (
         // initialize result and counters
         var bc = 0, bs, buffer, idx = 0, output = '';
         // get next character
         buffer = input.charAt(idx++);
         // character found in table?
         // initialize bit storage and add its ascii value
         ~buffer && (bs = bc % 4 ? bs * 64 + buffer : buffer,
            // and if not first of each 4 characters,
            // convert the first 8 bits to one ascii character
            bc++ % 4) ? output += String.fromCharCode(255 & bs >> (-2 * bc & 6)) : 0
         ) {
         // try to find character in table (0-63, not found => -1)
         buffer = digits.indexOf(buffer);
      }
      return output;
   };
})();

// Function.prototype.bind ?
(function checkFunctionPrototypeBindCompatibility() {
   if (typeof Function.prototype.bind !== 'undefined')
      return;

   Function.prototype.bind = function functionPrototypeBind(obj) {
      var fn = this, headArgs = Array.prototype.slice.call(arguments, 1);
      var bound = function functionPrototypeBindBound() {
         var args = Array.prototype.concat.apply(headArgs, arguments);
         return fn.apply(obj, args);
      };
      return bound;
   };
})();

// HTMLElement dataset property
(function checkDatasetProperty() {
   var div = document.createElement('div');
   if ('dataset' in div)
      return; // dataset property exists

   Object.defineProperty(HTMLElement.prototype, 'dataset', {
      get: function() {
         if (this._dataset)
            return this._dataset;

         var dataset = {};
         for (var j = 0, jj = this.attributes.length; j < jj; j++) {
            var attribute = this.attributes[j];
            if (attribute.name.substring(0, 5) != 'data-')
               continue;
            var key = attribute.name.substring(5).replace(/\-([a-z])/g,
               function(all, ch) { return ch.toUpperCase(); });
            dataset[key] = attribute.value;
         }

         Object.defineProperty(this, '_dataset', {
            value: dataset,
            writable: false,
            enumerable: false
         });
         return dataset;
      },
      enumerable: true
   });
})();

// HTMLElement classList property
(function checkClassListProperty() {
   var div = document.createElement('div');
   if ('classList' in div)
      return; // classList property exists

   function changeList(element, itemName, add, remove) {
      var s = element.className || '';
      var list = s.split(/\s+/g);
      if (list[0] === '') list.shift();
      var index = list.indexOf(itemName);
      if (index < 0 && add)
         list.push(itemName);
      if (index >= 0 && remove)
         list.splice(index, 1);
      element.className = list.join(' ');
   }

   var classListPrototype = {
      add: function(name) {
         changeList(this.element, name, true, false);
      },
      remove: function(name) {
         changeList(this.element, name, false, true);
      },
      toggle: function(name) {
         changeList(this.element, name, true, true);
      }
   };

   Object.defineProperty(HTMLElement.prototype, 'classList', {
      get: function() {
         if (this._classList)
            return this._classList;

         var classList = Object.create(classListPrototype, {
            element: {
               value: this,
               writable: false,
               enumerable: true
            }
         });
         Object.defineProperty(this, '_classList', {
            value: classList,
            writable: false,
            enumerable: false
         });
         return classList;
      },
      enumerable: true
   });
})();

// Check console compatibility
(function checkConsoleCompatibility() {
   if (!('console' in window)) {
      window.console = {
         log: function() {},
         error: function() {},
         warn: function() {}
      };
   } else if (!('bind' in console.log)) {
      // native functions in IE9 might not have bind
      console.log = (function(fn) {
         return function(msg) { return fn(msg); };
      })(console.log);
      console.error = (function(fn) {
         return function(msg) { return fn(msg); };
      })(console.error);
      console.warn = (function(fn) {
         return function(msg) { return fn(msg); };
      })(console.warn);
   }
})();

// Check onclick compatibility in Opera
(function checkOnClickCompatibility() {
   // workaround for reported Opera bug DSK-354448:
   // onclick fires on disabled buttons with opaque content
   function ignoreIfTargetDisabled(event) {
      if (isDisabled(event.target)) {
         event.stopPropagation();
      }
   }
   function isDisabled(node) {
      return node.disabled || (node.parentNode && isDisabled(node.parentNode));
   }
   if (navigator.userAgent.indexOf('Opera') != -1) {
      // use browser detection since we cannot feature-check this bug
      document.addEventListener('click', ignoreIfTargetDisabled, true);
   }
})();

// Checks if navigator.language is supported
(function checkNavigatorLanguage() {
   if ('language' in navigator)
      return;
   Object.defineProperty(navigator, 'language', {
      get: function navigatorLanguage() {
         var language = navigator.userLanguage || 'en-US';
         return language.substring(0, 2).toLowerCase() +
            language.substring(2).toUpperCase();
      },
      enumerable: true
   });
})();

(function checkRangeRequests() {
   // Safari has issues with cached range requests see:
   // https://github.com/mozilla/pdf.js/issues/3260
   // Last tested with version 6.0.4.
   var isSafari = Object.prototype.toString.call(
      window.HTMLElement).indexOf('Constructor') > 0;

   // Older versions of Android (pre 3.0) has issues with range requests, see:
   // https://github.com/mozilla/pdf.js/issues/3381.
   // Make sure that we only match webkit-based Android browsers,
   // since Firefox/Fennec works as expected.
   var regex = /Android\s[0-2][^\d]/;
   var isOldAndroid = regex.test(navigator.userAgent);

   if (isSafari || isOldAndroid) {
      PDFJS.disableRange = true;
   }
})();

// Check if the browser supports manipulation of the history.
(function checkHistoryManipulation() {
   if (!window.history.pushState) {
      PDFJS.disableHistory = true;
   }
})();
